Image display apparatus for writing display information with reduced electric consumption

Abstract

An image display apparatus for displaying gray-scale images by writing display information to an image display area of a panel. The display information includes values of a plurality of sub-fields that constitute one field. The image display apparatus converts an input image signal into a piece of display information so that a difference between sub-fields in correspondence with each other in adjacent high gray-scale levels becomes less. The image display apparatus displays a gray-scale image in accordance with the piece of display information.

1. An image display apparatus for displaying gray-scale images by representing each gray-scale level of the images by an ON/OFF pattern of a set of sub-fields constituting one field, the image display apparatus comprising:
 an input image conversion unit configured to convert an input image signal into image information; 
 a sub-field information generating unit configured to generate display information for each sub-field, based on the image information output from the input image conversion unit; and 
 an address driver configured to write the display information for each sub-field generated by the sub-field information generating unit, into an image display area, wherein 
 the input image conversion unit converts the input image signal by setting an area composed of a plurality of adjacent pixels in response to the input image signal, then if a luminance difference between main gray-scale levels in the area is no less than a first predetermined value, changing the luminance difference to no less than a second predetermined value. 
 
   
   
     2. The image display apparatus of  claim 1 , wherein the main gray-scale levels in the area form a regular pattern in units of pixels. 
   
   
     3. The image display apparatus of  claim 1 , wherein the main gray-scale levels in the area are two or less gray-scale levels for each display color, and form a regular pattern in units of pixels for each display color. 
   
   
     4. An image display apparatus for displaying gray-scale images by representing each gray-scale level of the images by an ON/OFF pattern of a set of sub-fields constituting one field, the image display apparatus comprising:
 an input image conversion unit configured to convert an input image signal into image information; 
 a sub-field information generating unit configured to generate display information for each sub-field, based on the image information output from the input image conversion unit; and 
 an address driver configured to write the display information for each sub-field generated by the sub-field information generating unit, into an image display area wherein 
 the input image conversion unit converts the input image signal by setting an area composed of a plurality of adjacent pixels in response to the input image signal, then setting a standard pixel in the area, then changing gray-scale levels of pixels excluding at least the standard pixel in the area so that the number of sub-fields that are different between the standard pixel and pixels adjacent to the standard pixel is restricted, and so that if a luminance difference between main gray-scale levels in the area is no less than a first predetermined value, the luminance difference is changed to be no less than a second predetermined value.